With the rapid network development and the increasing data amount, uniform distribution of data in a distributed system is the key to ensuring normal operation of the distributed system. For example, when a machine in the distributed system crashes due to an excessively large amount of data in the machine, all data in the machine cannot be accessed and needs to be migrated to another machine; as a result, the distributed system becomes unstable. Therefore, how to ensure uniform distribution of data in machines in the distributed system is a problem that urgently needs to be resolved.